Where n appears in A351495, or -1 if it never occurs.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =5a(6) =23a(7) =7a(8) =8a(9) =9a(10) =161a(11) =10a(12) =1771a(13) =12a(14) =11a(15) =16a(16) =23023a(17) =13a(18) =391391a(19) =14a(20) =15a(21) =19a(22) =7436429a(23) =17a(24) =18a(25) =21a(26) =20a(27) =24a(28) =171037867a(29) =22